A basic principle of realizing display of one frame picture by a thin film transistor-liquid crystal display (TFT-LCD) is as follows: inputting, by a gate driving circuit, a square wave with certain width to each row of pixels from top to down sequentially so as to gate this row of pixels; and then, outputting, by a source driving circuit, a required signal to each pixel of respective rows of gated pixels. In the existing display apparatus, the gate driving circuit is designed with a gate drive on array (GOA) circuit, which not only saves the cost but also realizes artistic design with two sides of the panel symmetrical, and at the same time can omit bonding area and peripheral wiring space of the gate driving circuit, so that the design of narrow frame of the display apparatus is realized, and productivity and yield rate of the display apparatus are raised.
At present, many types of input devices may be applicable to execute an operation in a computer system, such as a mouse, a button, a touch panel, an operating lever, a touch panel, etc. Due to usability, multi-functionality of operations, decreasing prices and stably rising yield rate of touch panels, they are becoming popular increasingly. The touch panel can be divided into out-cell and in-cell. An out-cell touch screen locates a panel having a touch function in front of a display, and a touch surface of this panel covers a visible area of the display, so as to realize touching and controlling. An in-cell touch screen integrates the touch function on the display panel, outside of which is coated with or without cover glass, and an operation can be implemented through touching the screen by a user's fingers.
In general, the GOA circuit comprises a plurality of shift registers connected in cascades. Compared with a display panel having no touch function, the touch screen needs to have both display function and touch function. Therefore, it is desirable that the shift registers in the GOA circuit of the touch screen are capable of being used to realize the display function and the touch function synchronously. However, in the existing shift register used for the GOA circuit of the touch screen, mutual interference exists between a display control signal and a touch control signal, such that adverse effect on the quality of display and touch would be caused respectively. In addition, an operation mode of the existing GOA circuit used for the touch screen is single, and has poor flexibility.